One of the highest honors a comic character can have is being part of multiple teams. It's a testament to a character's popularity when a hero like Teen Titans was about being with the team that defined him. But when the Justice League tried to kill a former Titan in JLA/Titans: The Technis Imperative, the Flash didn't hesitate in siding with the Teen Titans.
The miniseries from writer Devin Grayson and artist Phil Jimenez sees former Titans being abducted by strange metal pods. Everyone from Cyborg.
Cyborg had been growing less and less human with each ing year and had finally given up all organic components to fuse with an artificial hive mind known as Technis. He was abducting the Titans because a part of him wanted to rebuild his family. While reserve deal with the natural disasters, the League sends its strongest to Titans Island. Having put the pieces together, the League also deduces that Cyborg is behind everything happening, which becomes a problem when they finally run into the Titans. The League no longer sees Cyborg as a living being, and thus has no problem with killing him. Disgusted, Wally is the first to protest, telling the world's most powerful superheroes that Cyborg is his friend and that he won't let the League kill him.
The resulting fight is one of the best between two superhero groups. Tempest clashes with Superman, and Wally runs circles around Kyle Raynor. Of course, the teams end up working things out after the Titans appeal to the few remaining bits of humanity left in Cyborg. Using technology left to him by an old ally, Cyborg forms a liquid metal body and embraces his friends. With the crisis averted, the two teams reconcile and end up sharing drinks at Guy Gardner's bar.
Reading the comic twenty years later is a breath of fresh air. Marvel's poorly received Civil Wars don't feel as justified as this does. The League might initially seem callous in their decision to kill Cyborg, but their perspective makes sense. Cyborg was little more than a computer program at the time, one that could accidentally lead to the death of millions. But the Titans' position also makes sense. They know their friend is still there underneath all the technology, and even if there's a slim chance of saving him, they'll take it.
All of it gets to the heart of the main difference between the Justice League and the Teen Titans. While Justice League like Batman and Superman are friends, at the end of the day, most are just coworkers. The Titans on the other hand spent their formative years together. Even people who spent relatively little time with the team are still considered family. Given all that, it's no wonder Wally chose the Titans over the League.
JLA/Titans: The Technis Imperative shows that while Wally West's Flash might have been with the League to honor his mentor's memory, his bond to the Titans is what drives him to be a hero.
